Last Updated on October 3, 2022 by Grow with Bovees
If you are an experienced gardener or landscaper, you will know the importance of managing clusters of weeds and keeping them at bay when going about your regular lawn care routine.
This is where weed and feed products come in. Weed and feed products contain fertilizer as well as post- or pre-emergent herbicides, and knowing when to water after applying them is crucial for the best results.
Using them as weed killers is one of the most common ways to go about managing weed clusters in lawns and comes especially in handy when your lawn is in a weed crisis.
Fertilizer with herbicide together eradicates weeds while also boosting the health of your lawn and maintaining lovely green grass. This is one reason why it is such a popular product to use on lawns infested with leafy weeds.
Different brands on the market include Pennington, Scotts, BioAdvanced and Spectracide.
In this article we will discuss in detail when the right time is to water after the application of weed and feed to kill broadleaf weeds and promote green lawns. But first, let us briefly take you through the types of weed and feed you can use.
What Type of Weed and Feed Should I Use?
Weed and feed are categorized into two main types of product. They also come in different forms, namely liquid and granular form.
The two main types of weed and weed products are known as post-emergent herbicide weed and feed and pre-emergent herbicide weed and feed.
A post-emergent herbicide is a type of weed and feed product that is used to rid your lawn of already existing broadleaf weeds or established non-grassy weeds. Most weed and feed agents will contain this herbicide. On the product label, you will often see that it claims to kill weeds growing in your yard.
Examples of common weeds that you can use this product on would be clover, purslane and dandelion.
Note that they will not be effective invasive grasses and will only kill actively growing weeds.
Pre-Emergent Weed & Feed
A pre-emergent herbicide weed and feed product is commonly used to stop annual weeds and weed seeds from sprouting and developing. It will not kill established weeds but rather prevents weed invasions from developing by killing off varieties of weed seedlings.
An example of an annual weed is crabgrass, which can easily be prevented by using a pre-emergent crabgrass preventer weed and feed.
Note that this product will not be effective on already established weeds, but it will stop seed germination.
Identifying and understanding these two types of products is not only important for the type of weed you want to control, but also to know when to water and mow the lawn after application of the product.
Proper watering is of vital importance and remember, like with most plant products, too much weed and feed can be detrimental. It will not only kill weeds but healthy grass blades as well
Mowing After Applying Weed Control Agents
Take note that apart from watering correctly, mowing at the right time also plays a vital role when deciding to apply weed and feed products.
If you choose to use a liquid weed control product, it is commonly recommended to wait about 24 hours after application.
A granular weed control product — much like a granular fertilizer — often takes a bit longer to disperse. To be sure that the product has dispersed evenly and properly, be sure to wait about 48 hours before you mow your lawn.
When Should I Water My Lawn After Applying Weed & Feed?
When to water your lawn after treating it with a weed and feed product depends on which type of product you use. Watering times and amount of water all depends on whether you are making use of a pre-emergent or post-emergent weed killer.
Watering may also vary depending on whether you are treating cool-season grasses or warm-season grasses.
Continue on as we discuss the watering requirements of both types of treatments.
When To Water After Applying Post-emergent Herbicides Weed & Feed?
When applying a post-emergent herbicidal product, it is important to know that broadleaf weed herbicides that are found in the product penetrate the leaves of weeds, after which it is able to destroy the weed thus hindering the absorption of water and other processes such as photosynthesis.
This process happens in a span of roughly two days. It is therefore important to refrain from watering your lawn about 48 hours after you have applied the product.
If you water before this time frame, you risk the herbicide being washed off of the leaves and into the soil, making it ineffective against weeds.
Post-emergent weed and feed products commonly thrive in circumstances that are rather dry than wet. Although a slightly moist lawn at the time of application is beneficial, so that the granules stick to the leaves properly.
Do not forget to check the weather forecast before going about a weed and feed treatment. Even light rain is able to wash the product off the weed leaves.
When To Water After Applying Pre-emergent Herbicide Weed & Feed?
Opposite to using a post-emergent herbicide, a pre-emergent product needs water to be effective. It is therefore important that you give your grass a good watering after treating it with a pre-emergent weed and feed. This is to ensure that the product properly seeps into the soil. Pre-emergent weed and feed is usually applied in winter or early spring, before seeds germinate.
The herbicides in weed and feed together with water create a chemical barrier that prevents root growth and kills seeds.
The herbicide in weed and feed products that are classified as being pre-emergent, will remain in the ground for a few weeks and herewith prevents weed seeds from sprouting and developing their roots.
It is, however, important to ensure that you do not over water a treated lawn. Excess water may cause the product to be washed out of the soil rather than allowing it to seep in. When watering, make sure that the water does not start pooling. You should not notice any run-off or standing water.
Being aware of the pending weather conditions and rain predictions when using a pre-emergent weed and feed is not as important as when you are using a post-emergent product.
It is, however, advised to refrain from watering after a heavy rain shower on a lawn newly treated with a pre-emergent weed and feed product. Excessive water may lead to over watering, which, as mentioned above, will rob the product of working effectively.
How Soon Can You Water After Applying Scotts Weed & Feed?
Scotts Turf Builder is a popular lawn care product, and it is best applied to a moist lawn, after a light sprinkling with water from a lawn sprinkler or together with the morning dew. The moisture on the leaves will help the particles of the Scotts weed and feed to stick to them better.
After applying Scotts Turf Builder weed and feed to a wet lawn, it is important that you do not apply more water within the first 24 hours of application as this runs the risk of washing the product particles into the soil preventing proper leaf penetration.
Do not apply Scotts Turf Builder weed and feed if it is going to rain on the day; rather wait for dryer conditions if you want the most out of the product.
Conclusion on Lawn Fertilizer & Weed Control
This concludes our article on when to water your lawn after using a weed and feed lawn product.
You should now have a proper understanding of the different water schedules using a post-emergent herbicide and a pre-emergent weed and feed product.
Remember that the watering and mowing schedules differ in each weed control product and do not forget to always have a look at the weather forecast a few days in advance to get the most out of your product.
There are many weed and feed products on the market. Find one that works for you.
Use the products correctly, and you will achieve a beautiful lush green lawn, free of pesky broadleaf weeds.
If you are looking for an organic alternative to weed and feed rather than lawn chemicals, corn gluten meal may be a good choice as it is considered to be a natural pre-emergent agent.
Should you not manage, or you are having concerns with lawn care, we advise that you contact a lawn care professional or lawn care service. They are experts when it comes to the health of lawn grass.